1. Field of the Invention
The present invention relates to an electrical connector, and more particularly to an electrical connector that is capable of preventing solder wicking.
2. Description of the Related Art
At present, common soldering technologies adopted by industries mainly include a surface mount technology and a pin-through-hole soldering technology, and solders are generally used in a soldering process regardless of which soldering technology is adopted. However, there are still existing problems such as solder wicking, missing solder, or false soldering.
A conventional electrical connector adopting the surface mount technology in general includes an insulating body having an upper surface and a lower surface opposite to each other, and a plurality of containing grooves penetrated through the upper surface and the lower surface, wherein each of the containing grooves has a bump stopper extended from a sidewall of the containing groove and disposed proximate to the lower surface, and a solder stop portion extended laterally downward from the bump stopper.
The conventional electrical connector further includes a plurality of conductive terminals contained in the containing grooves respectively, wherein each of the conductive terminals has a base disposed at the bottom of the bump stopper and between the solder stop portion and the sidewall. The lowest point of the base is higher than the lowest point of the solder stop portion. The base has a contact portion formed thereon and extended upwardly from both sides of the bump stopper. A containing space is formed between the two contact portions and provided for passing the bump stopper and the solder stop portion. At least one soldering portion is formed separately at both ends of the base and extended downwardly from both ends of the base. A solderable metal layer is brush-plated at the periphery of the soldering portion.
And moreover, the conventional electrical connector includes a plurality of solders contained in the containing groove and contacted with the solder stop portion, wherein a side of the solder is in contact with the solderable metal layer.
During the process of assembling such a conventional electrical connector, each conductive terminal is installed from the lower surface into the corresponding containing groove of the insulating body, such that the bump stopper and the solder stop portion are passed through the containing space. When the base is situated between the solder stop portion and the sidewall, the lowest point of the solder stop portion is lower than the base, and then each solder is placed into the corresponding containing groove.
When the electrical connector is soldered onto a printed circuit board, each solder is heated and melted into a liquid state by a high temperature. A portion of the electrical connector is attached onto the soldering portion of the conductive terminal, and another portion of the electrical connector is attached onto the printed circuit board, so that the electrical connector is soldered onto the printed circuit board to constitute an electric connection. Since the containing groove contains the solder stop portion, and the lowest point of the solder stop portion is lower than the base, therefore the solder in the liquid state can be prevented from climbing up towards the base, in other words, preventing the occurrence of a capillary phenomenon.
However, the conventional electrical connector has the following drawbacks:
1. When the soldering portion is soldered onto the printed circuit board, the solder is heated into a liquid state by a high temperature and attached onto the solderable metal layer. However, the solderable metal liquid may be diffused during the brush plating process, such that the solderable metal layer and the solder cannot be controlled within a specific range easily. Moreover, the conductive terminal is entered into the containing groove from the lower surface, thus the bump stopper and the solder stop portion have to come with a size and a width fitting the containing space between the two contact portions, so that the conductive terminal can be entered and fixed into the containing groove successfully. Meanwhile, the solder stop portion cannot cover both ends of the base which are the positions of the base coupled to the contact portions. As a result, solder wicking occurs, and the solder in the liquid state flows along the portion of the base which is not covered by the solder stop portion and towards the contact portion with capillary phenomenon.
2. When the solderable metal layer is brush-plated onto the soldering portion, the solderable metal layer may be brush-plated onto the base as well due to technical or operating problems, and thus increasing the production cost, causing a solder wicking phenomenon easily during the soldering process, and resulting in a poor soldering effect.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.